Probabili impatti del cambiamento climatico sulla biodiversità delle foreste italiane

The likely impact of climate change on the biodiversity of Italian forests. Based on literature results andour expert evaluation, we report some likely impacts of climate change on the biodiversity of forest communitiesin Italy by the end of this century. In the Mediterranean region and on the Apennines: at low altitudes,vulnerability of Pinus sp. and Quercus ilex forests, with loss of intraspecific genetic variability; transition fromMediterranean closed-canopy macchia to scattered shrublands; risk of local extinction for coastal populationsof mesic/relic hardwood species (e.g., Quercus robur, Carpinus betulus, Zelkova sicula, Fraxinus sp.); ’eastern’relic species like Quercus troiana, Quercus frainetto, Quercus aegilops, and Q. gussonei in Sicily, and theperipheral low-altitude Fagus sylvatica populations, will be highly vulnerable; in the mid-altitude forest, vulnerabilityof most demanding species like Quercus cerris and Castanea sativa, possible immigration of Mediterraneanspecies like Quercus ilex; in the montane forest, Fagus sylvatica and Abies alba will be less competitivewith respect to more continental and drought-resistant tree species, and could loose genetic variability;relic species like Taxus baccata and Betula aetnensis may be at risk. In the alpine region: upward movement oftimberline and changes in timberline communities, for instance Picea abies may be more competitive over Larixdecidua, and fragmented species like Pinus cembra might become vulnerable. In general, we recognize thedifficulty in separating the effects of climatic variables from those of other processes, like fires and land-usechange.